In last month’s column, I discussed the importance of the Indoor Environmental Quality Credit 3.1 (IEQc3.1): Construction Indoor Air Quality (CIAQ) Management Plan-During Construction, one of two credits in the USGBC’s LEED rating system that deals with indoor air quality. I’d like to now touch on the other indoor air quality credit-IEQc3.2: CIAQ Management Plan-Before Occupancy.
The purpose of the IEQc3.2 credit is to protect all the occupants of the building once the construction work is complete. Since air quality issues can arise as a result of construction, workers on-site are required to follow a CIAQ Management Plan. Following this plan will not only help the project team acquire both indoor air quality-related credits, but will also protect the health of both the construction workers and future occupants.
The plan covers guidelines like dust control, the protection of ductwork, general housekeeping and materials storage. The plan also addresses other air quality topics, including keeping the volatile organic compounds (VOCs) out of the paints and adhesives used in the building.
The construction management plan addresses five main topics:
- Smoking-no smoking is allowed inside of the building during construction.
- Storage of materials-all absorptive materials should be kept off the ground and covered to avoid water or moisture damage.
- Housekeeping-daily housekeeping reduces dust and debris on the project site.
- Protecting the ventilation system-all open ends of semi-installed ductwork should be capped or sealed, and equipment should be covered to prevent dirt and dust from accumulating.
- Proper ventilation in the building during construction-adequate ventilation should be introduced into the building, and it should be suitable for the construction activities that are taking place.
The two different compliance paths for the IEQc3.2 credit will help ensure there will not be elevated levels of pollutants that could detrimentally affect the health and well-being of building occupants once construction is complete. To achieve this credit, the building must either be flushed with outdoor air, or a specialist should be hired to test the air quality inside of the building before the owner moves in.
The building flush-out compliance path requires 14,000 cubic feet of outdoor air be introduced for every square foot of building area, while proper temperature and humidity levels are maintained. There is also a staged flush-out method, which allows for occupancy after a certain portion of the 14,000 cubic feet/square feet of outdoor air has been introduced into the space. This can take days or weeks to complete. The rest of the outdoor air can then be introduced after occupancy.
As part of the LEED requirements for this compliance path, the mechanical trades may be asked to run the air handling equipment for a period of time, which will allow for the proper amount of outdoor air to be brought into the building. They will also need to change the filters on the ventilation equipment once the flush-out is complete. It’s important to note, when choosing this option, there could be a delay in occupancy due to the length of time needed for the flush-out, and there is a possibility for increased energy costs if the outdoor air needs to be heated or cooled, depending on the weather/season.
As an alternative, the air quality testing compliance path requires an industrial hygienist to come to the site and take air samples over a minimum period of four hours. Those samples are then sent to a lab, and the results are reported for various amounts of contaminants. LEED requires that all construction activities are complete before the testing begins. To meet the requirements, the following parameters must be measured:
- Formaldehyde-This compound, typically found in coatings and particleboard, should be under 27 parts per billion
(ppb). - Carbon Monoxide-The target level is less than 9 parts per million (ppm) and no more than 2 ppm above outdoor levels.
- Total VOCs-Paints and other materials used to finish the interiors of buildings contain VOCs. The acceptable amount is under 500 micrograms per cubic meter of air (μg/m3).
- Particulates-Baseline IAQ testing should show that these contaminates are less than 50 μg/m3.
- 4-Phenylcyclohexene (4-PCH)-The measurement of 4-PCH is required for areas where carpet or fabrics that contain styrene butadiene rubber backing has been installed.
One of the best ways to achieve the IEQc3.2 CIAQ Management Plan-Before Occupancy credit and limit the amount of toxins in the air is to follow the CIAQ plan during construction and stick to a low VOC-emitting strategy for the duration of the project.
There are several other construction practices that can be set in place during the construction phase that will be beneficial in helping the project team and owner achieve this credit as well. This includes implementing dust-control measures, restricting traffic or establishing a “no idle” policy to reduce tail pipe emissions from entering the building, making sure all containers of wet materials are closed after use, choosing electric-powered tools when possible and isolating areas of work during construction to prevent further contamination. Following the CIAQ plan and incorporating these techniques into your construction practices will go a long way in supporting the achievement of this credit.
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Thomas Taylor, a 30-year veteran of the construction industry and noted expert on sustainability, is a principal and co-founder of St. Louis-based Vertegy. To learn more about Vertegy or Taylor, visit www.vertegyconsultants.com.